Conventionally, a moving wireless communication device connects with a wireless relay device (a base station, an access point, or the like) with the best communication quality at initiation of connection, and starts communication with the connected wireless relay device. When the condition of communication with the wireless relay device with which the wireless communication device communicates gets worse, the wireless communication device performs handover to another neighboring wireless relay device, and starts communication with the new wireless relay device. When wireless communication between a wireless communication device and a wireless relay device is affected by an obstacle, the communication quality is degraded and handover needs to be performed again.
Patent Literature 1 discloses a method in which a moving object monitors whether or not an obstacle is present between the moving object and a base station in the moving direction of the moving object by using a monitoring camera or a sensor. In addition, when an obstacle is detected, the moving object of Patent Literature 1 recognizes the position at which communication with the base station will be disconnected, and maintains the communication by changing the communication method such as changing a communication speed or a modulation method.
In addition, Patent Literature 2 discloses a manhole type base station. Patent Literature 2 also discloses a method of mounting a pressure sensor or an electric wave sensor on a manhole to allow the base station to detect whether or not an obstacle is present on the manhole, and when an obstacle is detected, causing a child device performing communication to perform handover to another base station to maintain the communication.